H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling

H04L1/0025—Transmission of mode-switching indication

Abstract

In an adaptive modulation communication, a reception apparatus need not always operate the function corresponding to a mode (64 QAM) most sensitive to accuracy deterioration. In a spread spectrum communication system, a controller (104) reads a demodulation method from a control signal specifying the modulation method (QPSK, 16-QAM, 64-QAM) and according to the demodulation method which has been read, the following are controlled: the sample rate of an A/D converter (111) and a de-spreader (102), the number of pilot symbols used by a propagation path estimation block (106), and the number of pilot symbols de-spread by the de-spreader (102). Thus, when the demodulation method is other than the 64-QAM, the sample rate can be set in accordance with the QPSK or 16-QAM and there is no need of operating the function corresponding to the 64-QAM all the time.

Priority Applications (5)

Despreading device, the propagation path estimation apparatus, receiving apparatus and interference suppression apparatus, despreading, propagation path estimation, reception and interference suppression method, a recording medium recorded with the program and the program